I think that's a significant part of it, but there's also fashion to consider. It's hard to make a lot of money in games unless you're chasing the latest fashio

I think that's a significant part of it, but there's also fashion to consider. It's hard to make a lot of money in games unless you're chasing the latest fashions in graphics, design, content, console, etc. There are a fair number of indie developers who have chosen to avoid all of that and spend multiple years slowly growing a community around the development of a very different kind of game. A good example would be Wube Software and their game Factorio (factorio.com). They've spent the last six years working on the game (making it available as early access that whole time) and talking to the fans about it as they go. Compare that to a studio who spends three years working on FIFA 2018, releases it, and then immediately signs a contract to spend three years working on FIFA 2021.